來自Reddit
What you've described is likely due to the dividend you mention. For some context, there are a few scenarios that can cause your position's cost basis or gain and loss information to not be available. Typically, this happens when a dividend or capital gain distribution is paid out, or a distribution is being reinvested. A trade placed intraday will also temporarily change the cost basis display.
Our system typically updates overnight and should resume displaying your cost basis and unrealized gains and losses within a business day of this activity. Check out the "Important Information" section at the bottom of the page for additional details if you notice any special symbols or if the security is highlighted.